JP4511846B2 - Resin cap for milk candy - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a milk cap resin cap used to seal the mouth of a glass cup.

  Paper caps have been used for a long time as caps for sealing the mouth of milk candy, but in recent years, resin caps with better sealing properties have been used. Such a milk candy resin cap includes an annular seal portion fitted to the inner surface of the mouth portion of the milk candy and a skirt wall fitted to the outer peripheral surface of the mouth portion, and a lower inner peripheral surface of the skirt wall. A circumferential engagement protrusion that engages with a step portion on the outer peripheral surface of the mouth of the milk jar is provided. An opening tab is provided on a part of the skirt wall, and the opening is performed by picking up the tab with a fingertip and pulling it up.

  In order to improve the sealing performance of such a milk candy resin cap, it is necessary to firmly fit the annular seal portion of the cap and the skirt wall to the mouth portion of the milk candy. However, if the fitting is strengthened, it is difficult to pull the cap away from the mouth portion at the time of opening, which makes it difficult for elderly people and children with weak power to open the cap. Therefore, as shown in Patent Document 1 and Patent Document 2, two weakened portions are provided on the skirt walls on both sides of the tab, and when the tab is pulled up, these weakened portions are first cut to facilitate opening. A resin cap for milk candy has been proposed.

However, in such a conventional milk candy resin cap, when the tab is pulled up, as shown in FIG. 10, only the portion sandwiched between the weakened portions on both sides expands and the other portion engages with the mouth portion. It will be in a state as it is. In order to pick the tab and remove the cap from the mouth portion, it is necessary to remove the cap from the mouth portion at the left and right 90 ° positions where the width is widest when viewed from the tab. It will not come off and the tab must be pulled up further. However, since a part has already been opened in the state of FIG. 10, the contents may be spilled if the milk cake is not firmly held when performing such two-stage motion opening.
Japanese Patent Laid-Open No. 11-147550 Japanese Patent Laid-Open No. 11-188752

  The present invention solves the above-mentioned conventional problems, is easy to open even for elderly people and children with excellent sealing performance and weak force, and can be reliably opened in one operation. It was made to provide a resin cap for use.

The present invention, which has been made to solve the above problems, includes an annular seal portion fitted to the inner surface of the mouth portion of the milk candy, and a skirt wall fitted to the outer peripheral surface of the mouth portion, and a lower portion of the skirt wall. Integrated milk cowl resin with a circumferential engagement ridge that engages with a step on the outer peripheral surface of the mouth of the milk jar on the inner peripheral surface, and a tab for opening the cap on a part of the skirt wall A weakened portion that is broken by pulling up of the tab is provided on both sides of the cap, which bisects the skirt wall into a 180 ° region on the tab side and a 180 ° region on the non-tab side, and the weakened portion is provided on the skirt wall. It is characterized by comprising a notch having a V-shaped cross section with an opening angle of 60 to 120 ° formed opposite to the inner surface and the outer surface, and a notch having a trapezoidal cross section.

  The resin cap for milk candy of the present invention comprises an annular seal portion fitted to the inner surface of the mouth portion of the milk candy and a skirt wall fitted to the outer peripheral surface of the mouth portion as in the prior art. Since the inner peripheral surface is provided with a circumferential engagement protrusion that engages with a stepped portion on the outer peripheral surface of the mouth portion of the milk jar, it has excellent sealing properties. In addition, weakened parts that can be broken by pulling up the tab are provided on both sides of the skirt wall, which is divided into a 180 ° region on the tab side and a 180 ° region on the non-tab side. There is an advantage that it can be easily opened by one operation.

  FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a bottom view thereof, FIG. 3 is an enlarged cross-sectional view of a tab portion, and FIG. 4 is a cross-sectional view showing a state in which the milk bottle is plugged. The milk candy resin cap of the present invention is for sealing the mouth 2 of a glass dairy milk provided with a step portion 1 on the outer peripheral surface of the mouth as shown in FIG. The material is a soft synthetic resin, generally low density polyethylene (LDPE) is used, and the whole is integrally formed by injection molding.

  The resin cap for milk candy according to the present invention comprises a top plate 3, an annular seal portion 4 projecting from the lower surface of the central portion thereof, and an annular skirt wall 5 that hangs down from the outer periphery of the top plate 3, as in the prior art. It will be. As shown in FIG. 4, the annular seal portion 4 is a portion that is fitted to the inner surface of the mouth of the milk jar and enhances the sealing performance, and the skirt wall 5 is a portion that is fitted to the outer peripheral surface of the mouth of the milk jar. It is. The lower inner peripheral surface of the skirt wall 5 is provided with a circumferential engaging ridge 6 that engages with the step portion 1 of the outer peripheral surface of the mouth of the milk candy. If not extended, the engaging ridge 6 is prevented from being detached from the step portion 1. In addition, the engagement protrusion 6 is not provided in the part of the weakening part 10 demonstrated below.

  An opening tab 7 is provided on a part of the outer periphery of the lower end of the skirt wall 5. The tab 7 is for picking up with a fingertip and pulling it up, and in this embodiment, four triangular ribs 8 are provided between the skirt wall 5 and the tab 7. The tab 7 may be continuous, but a notch 9 may be provided at the center as in this embodiment.

  As shown in FIGS. 1 and 2, the skirt wall 5 is provided with two weakened portions 10 that are broken when the tab 7 is pulled up. In the present invention, the weakened portions 10 are respectively provided at positions that bisect the skirt wall 5 into a 180 ° region on the tab side and a 180 ° region on the non-tab side. These weakened portions 10 are provided at both side positions that bisect the skirt wall into a 180 ° region on the tab side and a 180 ° region on the opposite tab side, that is, at a position of 90 ° ± 10 ° to the left and right from the center of the tab 7. However, these weakened portions 10 are more preferably provided at a position of 90 ° ± 5 ° left and right from the center of the tab 7 and most preferably provided at a position of 90 ° right and left accurately. If the weakened portions 10 are respectively provided at such positions, the skirt wall 5 can be broken and separated from the mouth portion at the point farthest left and right when viewed from the tab 7 when the tab 7 is lifted. As shown in FIG. 5, it can be reliably opened by one operation.

  As shown in FIGS. 6 and 7, in this embodiment, the weakened portion 10 is constituted by a notch 11 having a V-shaped cross section and a notch 12 having a trapezoidal cross section, and is provided to face each other from both the inside and outside of the skirt wall 5. ing. The V-shaped notch 11 preferably provides an opening angle of 60-120 °, in this embodiment 90 °. On the other hand, it is preferable that the trapezoidal notch 12 has a circumferential width of the bottom surface of about 1 to 1.5 mm. Thus, by making one notch 12 wide, it becomes possible to absorb a slight deviation between the inner surface molding die and the outer surface molding die. In this embodiment, the V-shaped notch 11 is provided on the inner surface of the skirt wall 5 and the trapezoidal notch 12 is provided on the outer surface, but the inside and outside may be reversed.

  The thickness of the weakened portion 10, that is, the distance in the radial direction between the tip of the V-shaped notch 11 and the trapezoidal notch 12 is preferably 0.1 to 0.3 mm. If the thickness of the weakened portion 10 is less than 0.1 mm, the strength is insufficient, and there is a possibility that the weakened portion 10 may be broken at the time of plugging. On the other hand, if it exceeds 0.3 mm, the strength becomes too high, and it is difficult to be surely broken at the time of opening. In this embodiment in which the material is soft polyethylene, it is set to 0.2 mm. The longitudinal length of the weakened portion 10 (the length of the notch 11) is preferably 1.0 to 6.0 mm from the lower end of the skirt wall 5. If the length is shorter than this, a force is required at the time of opening, and if it is longer than this, the strength and sealing performance of the skirt wall 5 are impaired.

  Thus, in order to ensure that the weakened portion 10 is broken at the time of stoppering, it is necessary to reduce the wall thickness. In this case, as shown in FIG. 8A, a deep notch is formed only on the outer surface side of the skirt wall 5, as shown in FIG. 8B, a deep notch is formed only on the inner surface side of the skirt wall 5, as shown in FIG. 8C. In addition, three designs are possible in which notches are formed on both the inside and outside surfaces. However, the design of FIGS. 8A and 8B is not preferred.

  In order to explain the reason, a mold structure is first shown in FIG. A milk cap resin cap is formed by a cavity mold 21, a core mold 22, and a stripper mold 23 as shown in FIG. 9A. At the time of mold release, as shown in FIG. 9B, the cavity mold 21 is separated upward from the molded product, and the molded product is held by the core mold 22. Next, the stripper mold 23 pushes up the lower end surface of the molded product to separate the molded product from the core mold 22.

  Since the mold is released by such a method, the notch on the outer surface side formed by the cavity mold 21 needs to be provided vertically to the upper end of the molded product. Therefore, when a deep notch is formed only on the outer surface side of the skirt wall 5, the cap is thin as shown in FIG. 8A. However, the cap having such a structure has a portion of the skirt wall 5 where the weakened portion 10 is formed. It loses strength and is not practical.

  Further, when a deep notch is formed only on the inner surface side of the skirt wall 5, the inner diameter of the stripper mold 23 must be increased as shown in FIG. 8B, and the stripper mold 23 has a lower end surface of a very thin molded product. Since it will push up, it will not be possible to release the mold well. However, by providing the notches from both the inside and outside as shown in FIG. 8C, the stripper mold 23 can be easily released while maintaining the strength of the upper part of the skirt wall 5. For the above reasons, it is preferable that the weakened portion 10 to be cut at the time of plugging is formed by notches 11 and 12 formed opposite to the inner surface side and the outer surface side of the skirt wall 5.

  The resin cap for milk candy according to the present invention constructed as described above is broken by pulling up the tab 7 at both side positions that bisect the skirt wall 5 into a 180 ° region on the tab side and a 180 ° region on the non-tab side. Since the weakened portion 10 is provided, it can be easily opened by a single operation of picking and pulling up the tab 7 and does not require a conventional two-stage motion. In addition, as in the prior art, an annular seal portion 4 fitted to the inner surface of the mouth portion of the milk jar and a skirt wall 5 fitted to the outer peripheral surface of the mouth portion are provided. Since it has the engagement protrusion 6 in the circumferential direction that engages with the stepped portion on the outer peripheral surface of the mouth portion, it has excellent sealing properties before opening.

It is a top view which shows embodiment of this invention. It is a bottom view which shows embodiment of this invention. It is an enlarged vertical sectional view of a tab part. It is sectional drawing of parts other than the weakening part which shows a fitting state with a milk mouth part. It is a perspective view which shows the open state of the cap of this invention. It is an expanded horizontal sectional view of a weakening part. It is sectional drawing of a weakening part. It is sectional drawing which shows the design proposal of a thin weakened part. It is sectional drawing explaining a metal mold | die structure and a mold release state. It is a perspective view which shows the open state of the conventional cap.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Step part 2 Mouth part 3 Top plate 4 Annular seal part 5 Skirt wall 6 Engagement protrusion 7 Tab 8 Triangular rib 9 Notch 10 Weak part 11 V-shaped notch 12 Trapezoidal notch 21 Cavity type 22 Core Type 23 Stripper type

Claims (1)

An annular seal portion fitted to the inner surface of the mouth of the milk jar and a skirt wall fitted to the outer peripheral surface of the mouth, and a step portion of the outer peripheral surface of the milk jar on the lower inner peripheral surface of the skirt wall A resin cap for milk candy that is provided with a circumferential engagement protrusion that engages with the skirt wall and that is provided with a tab for opening the plug on a part of the skirt wall, the skirt wall being a 180 ° region on the tab side A weakened portion that is broken by pulling up the tab is provided at both side positions almost bisected into the 180 ° region on the opposite side of the tab and the opening angle formed by making the weakened portion face the inner surface and the outer surface of the skirt wall is 60 °. A resin cap for milk candy characterized by comprising a notch having a V-shaped cross section of ˜120 ° and a notch having a trapezoidal cross section .

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